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A Slight Tick for Urban Gardeners

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Some folks might not appreciate being known as "the tick guy," but ESPM's Robert Lane relishes the appellation. For nearly four decades Lane has studied ticks, particularly those that attach to humans. His work has been seminal in the field, growing the knowledge base about these pesky—and worse—disease-bearing critters.

Lane, a professor emeritus, recently shed yet more light on ticks.In the first study of its kind in North America, Lane moved his tick research from rural woods to urban gardens.

"Until this study, most of our research was conducted in undisturbed natural habitats, such as dense woodlands," Lane said. He and his research team shifted their attention to public gardens in the Bay Area to learn about human-biting tick populations closer to home, and to discover what, if any, risks they might pose to gardeners.

"To our surprise, we identified transmission cycles of Lyme disease spirochetes—spiral-shaped bacteria—similar to those in undisturbed wildland areas of Northern California," he said.

In an article in the July-August-September issue of Pacific Horticulture coauthored by Natalia Fedorova, Lane was careful not to cause undue alarm, noting that tick abundance doesn't necessarily translate to higher risk for gardeners.

"Not all ticks bite humans," said Lane. "Only the adult females and the poppy seed-sized nymphs normally attach to people." Some basic vigilance can help to neutralize the added risk factor. "Gardeners working where ticks abound should seriously consider wearing a pair of white overalls treated periodically with a tick repellent containing permethrin," Lane said, referring to the repellent ingredient that studies have found to be most effective. The light-colored clothing makes ticks more visible.

What about ordinary garden visitors? "If they stay on the trails and away from the beds, the risk is virtually nil," he said.

Lane also tamps down any undue alarm by noting that his study was limited to two public gardens: the University of California Botanical Garden and the Regional Parks Botanic Garden, both adjacent to wildlands in the Berkeley Hills. Further study is needed to determine whether tick populations are present in other metropolitangardens, he said.

-Ann Brody Guy

EUROPEAN TOURISTS: Another landmark study coauthored by Lane and Fedorova found evidence that a spirochete that was previously associated only with Lyme disease cases in Europe occasionally infects humans in California. Of approximately 18 described species of Lyme disease–group spirochetes worldwide, this is only the second known to infect people in North America. The study was spearheaded by Yvette Girard, a former Lane postdoc, and published in the March 2011 Journal of Clinical Microbiology.